Conveyor belt cleaners are used on conveyors for continuously cleaning the surface of a moving conveyor belt by scraping debris from the lower run of the conveyor belt.
Conveyor belt cleaners should be rugged in construction and unaffected by debris falling from the surface of the conveyor belt. Conveyor belt cleaners are typically mounted beneath the lower run of the conveyor belt where debris removed from the surface of the belt may be deposited thereon. Accumulations of debris on moveable parts and surfaces over which parts move may inhibit movement and cause accelerated wear of the surfaces and parts.
Conveyors used to haul coal in mines and in electrical power plants frequently include a water spray to minimize coal dust in the air around the conveyor. The water and coal dust combine to form troublesome sludge deposits on the conveyor belt which are difficult to remove. As a result, heavy duty conveyor belt cleaners are used to remove the sludge deposits from the surface of the conveyor belt. The abrasive nature of the sludge deposits cause rapid abrasion of the blades, and any moving parts of the cleaner upon which they accumulate. In addition, the accumulation of sludge deposits on surfaces over which parts move can cause parts to become jammed.
Service is periodically required on the blades and blade support apparatus of conveyor belt cleaners. The blades are subject to wear over time and require adjustment to compensate for the wear. Eventually the blades and blade support apparatus must be replaced. In some applications, service is required on a daily basis to keep the conveyor belt cleaner functioning properly. As the frequency of service increases, the ease of servicing the cleaner becomes more important.
The conveyor belt cleaner may be safely serviced by either stopping the conveyor belt to work on the scraper blades and support structure while underneath the conveyor, or by moving the scraper blades and their support members from under the conveyor. If the conveyor belt cleaner is serviced in its operative position, under the conveyor, the conveyor belt should be stopped prior to servicing. However, if the scraper blades and support structure are removed from the conveyor, the servicing operations may be performed while the conveyor continues to operate.
One way of making a conveyor belt cleaner that is serviceable while the conveyor belt is operating is disclosed in U.S. Pat. No. 4,249,650 to Stahura. In the Stahura patent individual belt scraper blades are affixed to concentric sleeve members which slide linearly upon a support member arranged transverse to the direction of conveyor belt travel. The individual belt scraper blades are interconnected by links and all of the blades are moved along the support member by means of a cable. While the scraper blades of this apparatus may be serviced beside the conveyor belt, dirt and debris may accumulate on the support member between the sleeve members, making it difficult to move the sleeve members along the support member. This is particularly true when many sleeve members are linked together to provide a long scaper blade because the sliding friction between the respective members increases with length.
If the Stahura device is used, dirt deposits between the sleeve and support member may abrade the surface of the support member or sleeve. Such abrasion causes accelerated wear on the members which loosens the fit of the sleeve on the support member. These problems are particularly apparent when the cleaner is used to remove abrasive substances from the surface of the conveyor belt such as coal dust or sludge.
Another disadvantage of such a device is that the cord used to move the sleeve members and blades along the support member can become entangled in trailers, or torn portions of the belt, resulting in damage to the belt or belt cleaner.
These and other problems encountered by prior art conveyor belt cleaners are overcome by the present invention.